Practice ammunition,particularly target image ammunition



R. NIEMANN 3,517,619

PARTICULARLY TARGET IMAGE AMMUNITION Filed Feb. 1, 1968 June 30, 1970 PRACTI GE AMMUNITION I INVENTOR. My

F 1 l1 -1 1| I I B 2 9 3 4 5 6 6 7 m 4 "M m F llili| United States Patent Int. Cl. F4zb 13/20 U.S. Cl. 10292.7 Claims ABSTRACT OF THE DISCLOSURE Practice ammunition comprising a target image projectile having a point or nose to the rear end of which is attached a disintegrating body consisting of a filling of metal powder or of compacted metal powder arranged in a jacket of plastics which has a bottom wall subjected to the pressure of a propellant charge. The open end of the jacket partially surrounds and extends along the rear section of the projectile nose and in the region of the filling the jacket is provided with an outwardly extending guide band which upon firing of the firearm is cut by the rifling in the barrel of the firearm.

The invention relates to practice ammunition, particularly to target image ammunition, the point or nose of which serves as the projectile fired at the target image and the weight of which conforms to a firing range of a desired shortened length, and which further includes a disintegrating body having a filling of metal powder or of at least one core of compacted metal powder.

Disintegrating ammunition has become known in which the projectile consists of a plastics jacket having a filling of loose metal powder, metal powder compacts, or the like. The plastics packet of the projectile is either made of one piece or is composed of two pieces suitably joined together, for instance by friction welding, and as a rule is provided with a guide band which, when the projectile travels through the barrel, engages the rifling in said barrel.

In such disintegrating ammunition the plastics jacket is frequently provided with notches or the like which extend parallel to the longitudinal axis of the projectile and promote the tearing open of the jacket when the projectile leaves the barrel of the firearm. It is also known to have the plastics jacket at least partially cut by the lands formed by the rifling in the barrel during the travel of the projectile through the barrel. On leaving the barrel, the plastics jacket tears open and the loose metal powder is dissipated. If as a projectile filling are used compacted metal powder cores, the same-after the projectile jacket has broken open-burst apart in consequence of the centrifugal forces due to the angular momentum produced during the travel of the projectile through the barrel and are dissipated by sudden air resistance forces.

Practice ammunition is to display as far as possible the same behaviour with respect to firing techniques as live ammunition. This applies especially to the feeding of cartridges to the firearm, to the recoil impulse and to the acoustic effects of firing. These requirements are essentially met by the known practice ammunition. The advantage of disintegrating ammunition lies in its complete dissipation a short distance in front of the gun barrel. Consequently, with disintegrating ammunition, also large caliber firarms having large horizontal ranges may be used on practice ranges of limited size for the purpose of training the armed forces in the operation of these firearms, on one hand, and for checking up on the functioning of these firearms, on the other hand. It is, however,

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not possible with disintegrating ammunition to train the gun crew in aiming.

In order to eliminate the disadvantages of disintegrating ammunition, there has been proposed heretofore a practice cartridge in which a light-weight projectile of a normal caliber, the weight of which is adapted to a firing range shortened as desired, is associated with a disintegrating body of the same caliber and an extension sleeve is inserted in the cartridge month which encases the disintegrating body and with its front edge grips the lightweight projectile. In this known type of ammunition, the extension sleeve holding the disintegrating body in the form of a metal powder compact is fixedly inserted in the cartridge mouth, and an axial duct extends through the disintegrating body which, on firing, makes a direct gas pressure charge on the metal powder compact possible, on one hand, and on at least a part of the rear end of the light-weight projectile, on the other hand. As a result of this gas pressure charge on the light-weight projectile, the same-when such as cartridge is fired-is torn out of its fixed place at the front end of the extension sleeve which is provided with a predetermined breaking point, while the extension sleeve itself remains in the cartridge mouth. The metal powder filling which, too, is subjected to the immediate gas pressure charge, disintegrates on firing of the gun and leaves the gun barrel in the form of a metal powder cloud. It is obvious that particles of the metal powder remain in the gun barrel and, when the next projectile is fired, act as an abrasive on the inner walls of the barrel. Unless practice barrels without rifiing are used for firing such practice cartridges, an extremely high wear with a corresponding lowering of firing precision is the inevitable result. In this respect the known practice ammunition for target aiming calls for improvements and such improvements are the object of the present invention.

According to the invention, the nose and the disintegrating portion of a projectile are joined together in a manner known per se, whereby the disintegrating portion is enclosed in a jacket preferably made of a plastics material so as to protect the explosive filling from propellant gases. Thereby it is made certain that a disintegration of the disintegrating portion during the travel of the projectile through the barrel of the firearm and therewith an escape of metal powder in the barrel is avoided.

In a further development of the invention, the jacket of the disintegrating portion may consist of a pot-shaped hollow container having a bottom which serves as a propeller base and the open front end of which-viewed in the direction of firingis engaged by the rear end of the projectile nose. Obviously, the practice projectile according to the invention may be provided with at least one guide band arranged at the disintegrating portion.

The practice ammunition according to the invention is so constructed that it corresponds essentially to live ammunition, for instance in regard of the initial projectile weight and the propellant charge. Thus the projectile has the same muzzle velocity as a normal projectile. ISince on firing only a part of the projectile, namely the disintegrating portion, is driven apart by e.g. centrifugal forces effective due to the angular momentum produced in the gun barrel during the passage of the projectile, only the rigid part of the projectile, such as the nose, is launched on a trajectory and passes through it compliance with the requirements for sufficient accuracy. By a suitable selection of the ratio of the masses of projectile nose and disintegrating portion, the trajectory and the horizontal range of the projectile can be predetermined. After disintegration of the disintegrating portion the kinetic energy of the rigid projectile portion and the kinetic energy imparted to the complete projectile at the instant of firing are at essentially the same ratio as the mass of the rigid projectile portion to the total projectile mass. Upon disintegration of the disintegrating portion, i.e. immediately in front of the muzzle of the firearm used for firing the projectile, the portion of the projectile entering a trajectory experiences a reduction of the ballistic coefiicient which in combination with a suitable shape of this projectile portion insures the desired velocity decrease.

A projectile nose or tip which has about the same caliber as the complete practice projectile or a live projectile, respectively, and which enters a trajectory is subjected to substantially the same air resistance as a complete projectile. The projectile nose, however, due to its lesser kinetic energy is slowed down more by air resistance than a complete projectile. In this manner the ammunition according to the invention may also be used on small practice ranges and it is made certain that the available safety zones are sufiicient.

According to another feature of the invention, the projectile nose may at least in part be of a smaller caliber than the barrel of the gun used to fire the projectile. The caliber of the projectile tip may be smaller than the gun barrel by twice the amount of the wall thickness of the jacket of the disintegrating portion. Also, the rear end of the projectile tip may have a section of a reduced caliber which is concentrically enclosed by the front end of the jacket of the disintegrating portion which contains a filling of metal powder, metal powder compacts, or the like.

According to another feature of the invention, the guide band radially projecting from the substantially cylindrical outer surface of the jacket of the disintegrating body may be arranged in the region of the filling consisting of metal powder or metal powder compacts.

Another significant object of the invention is an extension provided at the rear end of the projectile nose which extends, preferably from the reduced caliber section overlapped by the foremost end of the jacket of the disintegrating body, into the hollow space formed by said jacket and is embedded in its filling consisting of metal powder, at least one metal powder compact, or the like. This extension may be constructed in the form of eg a guide or tail unit having stabilizing surfaces which preferably abut the inside wall of the jacket of the disintegrating body in the region of the guide band. The extension may also be constructed as a rotation symmetric body, the diameter of which is reduced as compared to that of the projectile nose and which is provided with at least one annular groove-like transverse rib. The advantage of this arrangement is that the extension having at least one transverse rib leads to an increase of the air resistance forces acting on the projectile nose as soon as the velocity of the projectile nose in free flight falls below the speed of sound. This ensues an effective limitation of the possible maximum firing ranges. As long as the projectile tip is within the supersonic speed region, i.e. on the first part of its trajectory which is of special interest here, the resistance increasing effect of the extension is for all practical purposes insignificant. It is obvious that the extension may also have a number of transverse ribs.

In a preferred embodiment of the invention, the projectile tip and the filling of the disintegrating portion have about the same masses.

In the following the invention will be described in greater detail with reference to the accompanying drawings, whereby the invention should not be construed as being limited to the illustrative embodiments.

In the drawings:

FIG. 1 is a longitudinal sectional view of a first embodiment of the target image ammunition according to the invention, illustrating a part of the cartridge case and a part of the gun barrel with a rifling;

FIG. 2 is a longitudinal sectional view of a modified embodiment of the target image projectile according to the invention;

FIG. 3 is a longitudinal sectional view of another modification of the target image projectile having at the rear end of the projectile nose a guide or stabilizing device;

FIG. 4 is a cross sectional View of the guide unit along the line IVIV of FIG. 3, and

FIG. 5 is a longitudinal sectional view of a still further embodiment of the invention having arranged at the rear end of the projectile nose an extension which projects into the hollow space formed by the jacket of the disintegrating body and is embedded in the projectile filling.

Referring to FIG. 1, the practice projectile consists substantially of a solid nose portion 1 and a disintegrating portion 4. The case of the disintegrating portion 4 comprises a jacket 6 made of plastic whose front section 9 surrounds the rear section 3 of the projectile nose 1. The jacket 6 encloses a filling 5 consisting of metal powder or of compacted metal powder cores. The jacket 6 of the disintegrating portion 4 is provided with a bottom wall 7 preferably having a greater thickness than the cylindrical Walls. The jacket 6 is also provided with a guide band 8 which is arranged approximately at the center of the length of the metal powder charge 5 and which projects radially from the outer surface of the jacket and engages the rifling 13 in the gun barrel 12 during the travel of the projectile through the barrel. The projectile is attached in the usual manner to the neck of a cartridge case 10 of which only one half is illustrated in FIG. 1, as is the barrel 12 including rifling 13.

The nose portion 1 of the projectile is made of solid matter and has, like any other projectile, a cylindrical rear section 3 merging into a tip 2. The nose portion 1 has a smaller caliber than the barrel of the firearm. The front section 9 of the plastics jacket 6 encloses the rear section 3 of the nose portion 1 up to about one half of the axial length of the nose portion 1. The arrangement is such that the nose portion 1 plus the concentric sleeve formed by the front section 9 of the jacket 6 add up to the desired caliber. On firing the gun, the projectile is caused by the ignition of the propellant charge in the cartridge case 10 to enter the gun barrel, whereby the guide band 8 engages the rifling 13 which gives a helical twist to the projectile. In passing through the gun barrel the projectile is properly guided by the guide band 8 which is cut by the rifling in the barrel and by the substantially cylindrical outer surfaces of the plastics jacket. After the projectile has left the muzzle of the gun barrel, the plastics jacket of the disintegrating body 4 rips apart and the filling 5 contained in the latter is flung away sideways due to the action of centrifugal forces.

The tearing open of the plastics jacket 6 is brought about by known measures which do not form part of this invention. Upon disintegration of the disintegrating body 4 the nose portion 1 of the practice projectile enters a trajectory to eventually aim at a target image.

The FIGS. 2 to 5 illustrate modified embodiments of the projectile according to the invention. For like or similar parts are used the same reference numerals as in FIG. 1, except that in FIG. 2 the numerals are provided with (prime), in FIGS. 3 and 4 with (double prime) and in FIG. 5 with (triple prime).

In the embodiment according to FIG. 2 the nose portion 1 is provided with a cylindrical rear section 3' of a reduced axial dimension and a diameter which is less than that of the projectile caliber. The front section 9 of the plastics jacket 6' of the disintegrating body 4 engages merely the cylindrical rear section 3' having the reduced diameter. Contrary to the embodiment shown in FIG. 1, the nose portion 1 has the same caliber or diameter as the barrel of the gun in which it is to be used. The cylindrical outer surface of the nose portion 1 is flush with the outer surface of the plastics jacket 6'. In

other respects this embodiment of the projectile according to the invention is identical with that shown in FIG. 1.

The embodiment according to FIG. 3 is substantially identical with the embodiment illustrated in FIG. 2. However, the rear end of the nose portion 1" is provided with a guide or stabilizing device. This stabilizing device consists of an intermediary stem portion 14 which is connected with the rear section 3" of the nose portion 1" and carries at its rear end four radial wings 15. The edges of the wings 15 facing the end 3" of the nose portion 1 extend preferably somewhat inclined rearward and may be provided with a draft for assisting the angular momentum of the projectile in free flight, which draft acts in the same direction as the rifling in the gun barrel. The outer edges of the wings 15 which extend parallel to the axis of the projectile in the illustrated embodiment engage the inner cylindrical surface of the plastics jacket 6" in the region of the guide band 8" and are embedded in the filling contained in the plastics jacket 6". This is particularly illustrated in FIG. 4. In this embodiment the nose portion 1 and the stabilizing device 14, 15 are made of one piece. It is obvious that these parts may be manufactured separately and subsequently be united with each other in any desired manner.

The modification of the projectile shown in FIG. 5 coincides to a large extent with the previously described embodiments. Instead of the guide or stabilizing device according to FIG. 3, however, the nose portion 1" is provided at its rear end with a substantially cylindrical stem 16 having annular grooves therein and which projects into the hollow space formed by the jacket 6 of the disintegrating body 4" and is embedded in the filling 5. This stem 16 has a series of annular concave grooves 17 forming rather pointed annular ribs 18. Preferably, the diameter of the stem 16 is reduced with respect to the end section 3" of the nose portion 1" by such an amount that the pointed ends of the annular ribs 18 are disposed only a small distance away from the inner wall of the plastics jacket 6". Again, the nose portion 1" and the stem 16 may be made of one piece or may be separately manufactured and later united with each other in known manner.

What I claim is:

1. In a target practice ammunition, a massive nose member serving as a target bullet the weight of which conforms to a desired shortened firing range, a disintegrating body comprising a filling of metal powder attached to said nose member and adapted to disintegrate immediately upon leaving the barrel of a firing weapon, and a jacket of plastics surrounding said disintegrating body and a portion of said nose member, including the rear end of the disintegrating body for protecting said filling from the propellent gases, said nose member having a smaller caliber than the barrel of the firearm used for firing said projectile.

2. A practice ammunition according to claim 1, in which said nose member has a caliber which is smaller by twice the amount of the wall thickness of said jacket than the barrel of the firearm used for firing said projectile.

3. In a target practice ammunition, a massive nose member serving as a target bullet the weight of which conforms to a desired shortened firing range, a disintegrating body comprising a filling of metal powder attached to said nose member and adapted to disintegrate immediately upon leaving the barrel of a firing weapon, a jacket of plastics surrounding said distintegrating body and a portion of said nose member, including the rear end of the disintegrating body for protecting said filling from the propellent gases, and a stabilizing device comprising a stem connected to the rear end of said nose member and extending into said filling of metal powder more than one half of the axial length of said filling, said stem including its end face directed toward the rear end of the jacket being completely embedded in said filling of metal powder in said jacket.

4. A practice ammunition according to claim 3, in which said stem is provided with radial guide wings which in the region of a guide band on the outer surface of said jacket engage the inner wall of said jacket.

5. A practice ammunition according to claim 3, in which said stem has a diameter which is less than that of said nose member and is provided with at least one annular rib.

References Cited UNITED STATES PATENTS 3,338,167 8/1967 Iungermann et a1. 102-92.7

192,829 7/1877 Hotchkiss l0292.2 3,141,412 7/1964 Roehrdanz 10293 3,242,865 3/1966 Jungermann et al. 10292.7

FOREIGN PATENTS 1,196,995 7/ 1965 Germany. 1,262,830 3/ 1968 Germany.

ROBERT F. STAHL, Primary Examiner 

